I tried to do it, and it was rough. Your coworkers are pulling up looking like a million bucks, and you look like you rolled out of the attic.
Ironing on a boat? Yeah, right.
Lots of pressed clothes? Psshh.
Not having everything smell like boat? lol
And the shower thing doesn't make it much easier either. I've messed around with various shower systems, but the one I'm going to try next will consist of a 5 gallon solar shower srapped on deck above the head. I'm going to lead the line through the portlight (make it easy on myself; if it works, I'll run it through the dorade or something). Figure it should be warm enough, on most days, by 3 in the afternoon or so.
So even though there's a good solution, you have a limited window of when to work with it.
The backup approach will be the bug sprayer bottles larry and lin style with some kettle warmed up water added to normal temperature. That should work for the lesser than wonderful weather.
In regards to the statements slamming showers as a land joy that has no place on a ship considering its shortcomings, I'd just like to say that we all have the things that make us happy in this world. The same person who might be telling you that a shower is absurd might have an ssb radio that someone else might find is overkill.
If a shower is something that will add to your happiness and sailing joy, as it does mine, make sure you set it up right.
In regards to the moisture, that is a problem. But it can be mitigated to some degree by wiping down, not making a mess in the first place by spraying everywhere, and perhaps even taking your showers seated or sitting down on the grate. It's hard to balance anyway while standing and holding a shower head in one hand.
And beyond that, just install some extra vents. If you have a dorade box for bad weather and a 24hour solar vent panel for the majority of the workload, you'll have a decent air flow going on. One step further you can try to mount a cabin heater on the opposite bulkhead wall. Then you can even punch a small hole (big enough for a pc fan, for example), that can draw air in from the warm and dry cabin heater area into the head.
Like I said, people can make fun of you for getting elaborate, but like I said they have their own quirky habits, which of course make perfect and reasonable sense to them.